sam85iroc

Let’s say we have an average 3,500lb Camaro with stock size rubber making around 260-360 HP and TQ... so basically your run of the mill 3rd gen with a few power mods... You don't want a perpetual downshifter with a 2.anything, but you also don't want to sound like you're stuck in first with high 4.xx gears either. You just want good mileage, to stay in your torque band, and still be able to haul ash...

What gear would you use? (please list for auto and manual)

Disclaimer-> I did a search but didn't find anything comprehensive...

sam85iroc

any thoughts on why a particular gear? personal experience? highway rpm vs. 1/4 time, etc...

PontiacMC

I have 3.73s in my 4th gen and just love them. The car is auto and I can still go 70mph just short of 3grand. The down shifts are a bit different then the 3.42s I had in it but it doesnt hurt my power band.

Orr89RocZ

iTrader: (20)

I've had 2.77's, 3.27's and 3.42's all behind my bolt on L98 that was around 3400lbs with me in it on race wheels... used them for highway, racing, daily driving, performance driving, etc...

My favorite was 3.42s with stock rubber. Still get good mileage and plenty of performance. There was a good noticeable difference between each step up. If you have 2.73's go for 3.42's. If you already have 3.23's well, its up to you if you want to spend the time/cash to upgrade to 3.42's. The gains are there but not as noticeable as going from 2.7x to 3.42. Only reason i went 3.42's was because I broke the 9 bolt 3.27's posi and didnt want to mess with trying to find 9 bolt parts..i went 10 bolt from a 4th gen with fresh 3.42's

I ran 3.42's on my 383 and my twin turbo motor until I broke the worm gears in the posi...great gears

EDIT...3.42's for automatic or T5's... 3.73-4.10's for T56 cars because of the deep overdrive.

eseibel67

Orr89 is right:

3.42 with 5 speed, 3.73 with 6 speed. If you're looking for compromise with emphasis on performance, this is it.

hellz_wings

iTrader: (2)

Went from 2.77 open diff (or wtv the stock 10 bolt 2.xx ratio is) to a Eaton 3.73 Posi-Traction. What a world of a difference! I drove it without a speedo for a long time and realized that my mileage on the highway was suffering because the overdrive wasn't properly engaging... So I got the correct driven gear for 3.73's in the tranny tail-shaft (i forget how many teeth it was..) and it drives very smoothly on the highway even with the 3.73's. This is with 700R4 auto.. For me, going up to 70MPH is around 2500RPM with stock IROC rims and 245/50/16 tires @ 32PSI.

AlkyIROC

Mid 3.xx range is usually a good ratio but it also depends on what your goals are plus other factors such as transmission gears and tire size. Running 2.77 or low 3.xx gears with a T56 and you'll probably never use the OD gears, acceleration off the line would be slow but you would get fantastic fuel mileage. 4.10 with a 3 speed tranny and the engine would be screaming down the highway but it would be a fun stoplight to stoplight car. Bump the tire size from the factory 26" tall to a 28" tall tire and the required ratios all change.